An international group of marine experts fears many shark populations are in rapid decline because of overfishing and an alarming increase in the lucrative fin trade.

The Shark Specialist Group is meeting on Queensland's North Stradbroke Island to compile information on the likelihood of extinction for shark species across the globe.

The group's spokeswoman Rachel Cavanagh says with an estimated 100 million sharks killed last year more must be done to conserve the species.

"There's no simple answer, so you've got to have things like a variety of strategies, such as fisheries management, " she said.

"You've got to persuade the fisheries managers that this is a real problem and they need to have quotas and they need to close off areas at certain times of the year if that's thought to be necessarily."